ATCO Electric is proposing to build new power transmission facilities on the east side of the province. This project includes:
- A new power transmission line between the Gibbons-Redwater area northeast of Edmonton and the Brooks area southeast of Calgary. The new line will be built and operated as a 500 kilovolt (kV) high voltage direct current (HVDC) line and run approximately 500 kilometres in length.
- A new converter station and related facilities at each end of the new line, to convert power from alternating current (AC) to direct current (DC) and to connect the new facilities to the Alberta electric transmission system.
Proposed Converter Stations
A converter station is needed at each end of the line to convert power from alternating current (AC) to direct current (DC), and from DC to AC.
The northeast converter station is to be located near AltaLink’s planned Heartland substation in the Gibbons-Redwater area. The southeast converter station is to be located near transmission lines in the vicinity of AltaLink’s existing West Brooks substation in the Brooks area.
Each of the converter stations will consist of a fenced area of approximately 500 by 500 metres (1640 by 1640 feet), containing transformers, breakers, converter valves, reactors, filters and related support equipment and structures.
Each site requires enough property to accommodate the converter station, the incoming HVDC line, and the 240 kV or 500 kV AC lines that will connect the converter stations to the existing transmission system.
500kV HVDC Transmission Line
The new ±500 kV HVDC bipole transmission line will be built between the Gibbons-Redwater area northeast of Edmonton and the Brooks area southeast of Calgary. Depending on the final route, the line will be approximately 500 kilometres in length.
This line will consist of two sets of conductor wires (each set being a “bundle” of four wires), a bundle of two neutral wires, and two overhead shield wires, all strung on steel lattice towers. The typical structure will be approximately 39 metres (128 feet) tall and approximately 27 to 29 metres (89 to 95 feet) wide at the arms. The base of the structure will be approximately 10 to 13 metres (33 to 43 feet) square.The typical distance between structures will be about 365 metres (1200 feet).
Wider and taller structures are required where the line ends or bends or to go over and around obstacles. In all cases minimum clearance will meet or exceed the requirements of provincial safety regulations.
Typical Right-of-Way
The area where transmission lines are located must be kept clear of trees and other obstacles. This area is called a “right-of-way”. The right-of-way must have a minimum width to ensure safe separation from other development and to allow access for construction and maintenance. Typical right-of-way widths and structure placements are shown on the diagrams below. Details may change with the final design and actual locations.
Additional right-of-way may be required for locations that require larger structures, removal of taller trees, or where practical access to or along the right-of way is outside the standard width.
* Additional right-of-way may be required for vegetation clearing.
*Proposed right-of-way widths may very with final locations and designs